双歧杆菌抑制小鼠实验性结肠炎肠道炎症反应的研究

The research on bifidobacterium inhibits inflammatory response in murine experimental colitis

目的观察补充益生菌对葡聚糖硫酸钠(DSS)诱导的小鼠结肠炎的影响,探讨益生菌对结肠炎的治疗作用和可能机制。方法将小鼠分为4组:正常对照组、DSS组、柳氮磺胺吡啶(SASP)组和双歧杆菌组。建立小鼠急性DSS结肠炎模型。SASP组在饮DSS水同时予SASP灌胃。双歧杆菌组在实验开始前7d予双歧杆菌灌胃至实验结束。每天观察各组疾病活动指数(DAI),并在实验结束后检测各组小鼠炎症肠段肿瘤坏死因子(TNF)α、核因子(NF)κBP65、髓过氧化物酶(MPO)等的表达。结果自实验第4天开始,SASP组和双歧杆菌组DAI明显低于DSS组。实验结束时,SASP组和双歧杆菌组炎症肠段TNFα[(10.01±1.11)和(10.45±0.98)pg·mg-1·ml-1]、MPO[(3.21±0.20)和(3.24±0.16)U/g组织]等的水平较DSS组[(13.35±1.01)pg·mg-1·ml-1和(3.63±0.23)U/g组织]均明显降低,NFκBP65阳性的炎症细胞数减少。结论给小鼠预服双歧杆菌能有效抑制炎症肠段炎症细胞NFκB的活化及炎性细胞因子的分泌,减轻肠道炎症反应。

Objective To investigate the effect of bifidobacterium (Bif) supplementation on acute inflammatory response in murine dextran sulfate sodium(DSS)-induced colitis, and its possible mechanism. Methods Mice were divided into four groups: control,DSS, salfasalazine (SASP) and Bif. The mice in groups DSS, SASP and Bif were fed with 5% DSS(w/v) solution for 7 days to induce colitis, and disease activity index (DAI) was calculated every day. The mice in group SASP were fed with SASP every day during inducing colitis, and the mice in Bif group were given Bif by oral gavage from 7 days before the experiment to the end of experiment. The expression of TNF-α、NF-κB P65 and myeloperoxidase (MPO) in inflamed colon of each group was measured at the end of experiment. Results The mice in groups SASP and Bif showed a lower DAI than those in group DSS since the forth day to the end of experiment. There were lower level of TNF-α and MPO in murine inflammatory colon, and lower NF-κB P65 expression in nuclei of inflammatory cells in groups SASP and Bif than those in control at the end of experiment. Conclusions Treatment with Bif can effectively inhibit proinflammatory cytokine secretion and NF-κB activation in inflammatory cells, and decrease colonic inflammatory response in DSS induced colitis.